The Atom and Elements

All matter consists of basic building blocks called atoms. Each atom is one of the many chemical elements, determined by the number of protons in the nucleus

• Basic Structure of Matter
• Atoms and Elements
• Subatomic Particles
• Atom Models
• Stable and Unstable Atoms
• Atomic Number and Mass Numbers
• Elements

Electrons surround the atom and bind it to other nearby atoms

• Electrons
• The Valence Shell
• The Free Electron

Atoms can be grouped into molecules. They can also exist with different numbers of neutrons (isotopes) and more or fewer electrons (ions).

• Molecules and Compounds
• Chemical Formula
• Isotopes
• Ionization